Dry-kiln.



o. vH. DINGMAN.

I DRY KILN. APPLICATION FILED IAY 16, 1909.

mm W Gru @WH nn wn -Za E 1V, DL mmY ma fn m N h aries Patented 1300.20, 1910.

s SHEETS-amm* 2.

' C. H. DINGMAN.

DRY KILN.

JLPPLIonIolr FILED In 15, 190s.

o; H. DINGMM.l

. DRY KILN. APPLIUATION FILED HAY 15, 1909.

Patented Dec. 20, 1910;

3 SHEETS-SHEET 3.

Wi n ass es UNITED sTATEs PATENT OFFICE. A

-cHARLEs II. DINGMAN, or MARION, MICHIGAN, AssIGNoR ."ro WALSH MANUFAC- TUBING cMPANY, o'r PITTSBURG, PENNsYLvANIA, A coRPoRA'rIoN or PENN- SYLVANIA.

Specification of Letters Patent.

To all whom it may concern: l

Be it known that I, CHARLES H. DINGMAN,

a citizen of the vUnited States of I-Xn'ierica,

residing at Marion, in the county of Osceola and State of Michigan, have invented certain new and useful Improvementsin Dry- Kilns,`of which the lfollowing is a specification, reference being had therein `to the.

A tional plan View thereof;F ig. 3 is a plan of a `portion of the kiln below the plane of the radiators; Fig. 4 is a Vlongitudinal lio section through Fig. 3; and Fig. 5 is a section in the plane of the outletduct.

In the drying of lumber, itis important to complete the process in as short a time interval as possible. Itis equally important to secure uniform drying and` particularly that the center should beasfthoroughly seasoned asthe surface portions. VVit-h my improved construction Ijsecure ,the desired results by subjecting the materiales it is first fed into the kiln to a sweating process in an atmosphere ladenlwith moisture from the lumbergpreviously treated, and in then feeding the material slowly through the `kiln and subjecting rit. to an `atmosphere constantly decreasing in humidity, until finally it comes in contact with the dry heated ir', which completes the process. The conditions just described are maintained in the kiln by the peculiar construction and arrangement of the heaters, and

the means employed for forcing the circulation 'of the `air as wlll be hereinafter described.

- In detail, A is the building which is contructed to be as nearly air tight as possi` ble, and is providedat opposite ends withk removable doors or curtains B and C respectively permitting the insertion and withdrawal of the lumber. The. walls of the building ,y are preferably supported upon cement foundations D andP at opposite points near the opposite ends of the kiln are arranged air lues E `and F. These are .preferably formed by cement walls extending across the kiln and aL short distance 'beyond Patented Dee. 20,' 1910. Applicatiouled May l15, 1909. Serial No. 456,311. l

has arranged therein fans .H forforcingv an air circulation.

For supporting the work, longltudlnally extending' track timbers I-are arranged to extend the entire length of the kiln and are supported upon a series of .posts or col-' umns J.

'-K are heater coils arranged" to extend longitudinally of the kiln, both inside and outside of the track timbers, which coils are connected to headers L at opposite ends thereof. *The coils K extend frolnthe opposite ends of the kiln for a` portion of the length thereof, but-are separated from each other Iby a central portion` M in the kiln, in which" there are no heaters.

there is also a flooring N covering vthe flue F and its extension F. Beneath this floorlng ythere are arranged heater coils' O, which,

This central portlon 1s covered with a flooringM, and

togetherwith the coils K atopposite ends' of the kiln, are connected in one system, wluch may be supplied with either exhaust l or .live steam.

IVith the construction 4as .thus far de` scribed, the temperature of the air within the kiln is maintained at the proper point by the heaters K, while ,the heater O serves to preheat the air entering the kiln through the flue F.l This air is caused to enterv said flue by the withdrawal of the air from the opposite end of the kiln through the flue in which, as previously stated,v are arranged the fans H as well as the connection to the stacks G.` Thus theinlow of the heated air 'may b e accurately regulated by suitable adjustment in the operation ozf the fansf The airentering through the iue F first tudinally through thekiln, until the lpoint of communication withthe flue E is reached` where 1t wlll pass mtosaid flue and be expelled. The main point of communication with the flue E is 'through' apertures l" formed in the floor M, which are arranged across the kiln nearone end of said oor,

and are adjustable in area by shutters Q. Through these apertures the air can ass downward beneath theradiator K and 1nto the Hue E, which is preferably provided with a grated covering for effecting more uniform distribution of the heat thereover. Afpartition R is arranged across the kiln below the flooring M to cut 0H any longitudinal circulation beneath said Hoor, and there is also a deHector S beyond the Hue E for interruptin any currents on the outer end of the kiln.

It will beunderstood from the description just'ngiven -that the only means for causing a lon itudinal movement of the air. within the ki n is the withdrawal of the air through the Hue E and acorresponding ingress of air through the Hue F. This will cause a constant slow movement from the right hand end of the kiln toward the left, until the apertures P are reached, and then the movement will be downward through said apertures and beneath the hea-ter K to the exit Hue. Thus, above the heater there will be formed substantially a dead air space, in

which there is very little longitudinal move-y ment of air, although a slight circulation will be produced by the passage of the small portion of air downward between the coils of the heater R.` The effect of this upon the drying of the lumber will be as follows: The green lumber is irst placed in the kiln at the lefthand side and is permit-ted to remain for a certain length of time in the dead air space at that end of the kiln. Here the green lumber will be subjected to the heat of the radiator K, as well as the humid atmosphere laden with the moisture from the previously treated lumber so that a sweating treatment will be produced. This treatment continues as long as the lumber remains in the zone of the kiln between the lefthand end and the apertures P, but as it approaches the latter point there is a slight clrculation of air due to the small portion that is withdrawn between the heater coils to the Hue E. After passing beyond the a ertures P the material is subjected to a s owly moving body of air, which becomesV drier asithe righthand end of the kiln is approached, and finally at the extreme righthand end the lumber is subjected to the preheated dry air directly entering to the Hue F.

In addition to the longitudinal movement of air due to the operation of the fans I-I there is an up and down movement produced by the heating eH'ect of the radiators K at thebottom of the kiln and the cooling due to absorption of the' moisture and loss of heat through the sides and top of the buildlng. This will resultin a constant up anddown circulation over the entire area above each of the radiators K, but over the central Hoor portion M ofthe kiln where there is no radiators there will be merely a forward movement of air as a body. In this zone, the cooling of the air will cause it to stratify the heavy moisture laden ,portions, finally passing downward throu'ghthe apertures P, and being expelled from the kiln. Thus by suitably regulating the fans H the most favorable conditions of humidity may be maintained in the various portions of the kiln but produce the gradual drying and the seasoning of the center vas well-as the surface portions.

A variation in the length of the dead air space may be eH'ected by adjusting the shutters Q to limit `the area of the apertures P. This will'restrict the air circulating through said apertures, and will compel the movement of the air body farther' forward and downward between the coils of the radiator K, but the eH'ect will 'not extend forward of the Hue E, as the deHectorl S will interrupt movement of the air from this portion. I would, however, preferably provide ventilator openin U in the forward side of the outlet duct and by suitably adjusting dampers U', controlling these apertures, -a

small quantity of air is permitted to pass Idrawn oil at the lumber entrance end. As

shown, E is an extension of the Hue E, similar to the extension F of the Hue F, but the outer end of this extension-instead of remaining open-is closed by a door V. Thus, under ordinary conditions, where the door V is closed., the kiln operates as has been above described, but where the door V is open then the air will be drawn from the extreme end of the kiln, which will cause the continuous movement of the body ol air within the kiln toward that end. The Hue E is provided at the top with an adjustable member W, which permits of closing the apertures when the circulation is desired throughout the entire length of the kiln.

Y As has been described, the kiln is provided with bot-h a stack connect-ion G and the exhaust fan I-I. Economy can be ef? Ifed from vone end to the other, means for heating the air within said housing in the end portions thereofwith an intermediate zone unproyided with heating means, means for causing a movement of the air bodily through the housing from ,the exit end toward the inlet to a point at the forward end of said unheated zone, and for there disy charging the moisture-laden airfrom the housing. c

2. A' dry kiln comprising a housinr through which the lumber to dried is fed from one end to the other, cross iues `ar ranged at the base of said 'housing near the opposite ends thereof,l said flues communicating with the external atmosphere, a -lue leading from one of said cross tlues -to the exit end of the housing a heaterin said f iue and a fan in the other liuefor withdrawing the air therefrom.

3. A dry kiln comprising \ahousing through which the lumberfito'be dried 1s f ed from one end to the other, means for maintaining a heated zone within said housing at opposite ends thereof with an intermediate zone therebetween unprovided with heating means, and means for causing the forward movement of the air from the exit end of the housing from the heated zone adjacent.

the exit end and the unheated zone, and for maintaining a substantial. dead air space over the zone adjacent the inlet end.

4. A dry kiln comprising a housing through which the lumber to be dried is fed from one end to the other, heaters arranged at the base of said housing, at opposite ends thereof, and intermediate tloored zones unprovided with heating means, air flues eX- tending across the base of said housing at opposite ends thereof, a iiue connecting with one of said air lues and extending to the exit end of said housing, a preheater forthe air within the last-mentioned flue, means for causing the Withdrawal of the air from the opposite flue.

5. A dry kiln comprising a housing through which the material to be dried is fed from one end to the other, means for heating the air within said housing, an inlet air flue communicating with the eXit end of said kiln, an exit air flue at 'the opposite end of said kiln, a fan for drawing out the air through said exit ilue, and a stack operating as an auxiliary to said fanfor draW- ing out the air. v

6. A dry kiln, y comprising a housing through which the material to be dried is fed from one end to the other, means for heating the air Within said housingv in the end portions thereof, with an intermediate zone unprovided with heating means, an

- outlet duet for the air in 'communication' with this unheated zone, and an auxiliarv outlet in the heated zone of the inlet end. u

7 A dry kiln, comprising a housing through which the lumber to be dried is fed `heating the air'before it is admitted to fromv one end to the other, means for heating'the air within said housing, means for admit-ting air at the exit end of the housing, and means for `preheating the air as it 1s admitted to the housin means for dischargingthe moisture-laened air at a point intermediate said air inlet-and the lumber inlet, and means for maintaining a dead air zone at the 'inlet endof said housing.

8. A dry kiln, comprising a housing through which the lumber to be dried is fed from one end to the other, means for heating the'air within the housing, an air flue for admitting air to the exit end of the housing,means within said flue for prethe housing, and means for discharging jmoismediate t-he exit and inlet ends of said housing, posit-ive means. for forcing the air circulation, and means for maintaining a dead air-zone at the inlet end of said housing.

10. A dry kiln comprising a housing through which the material to be dried is fed from one end to the other, a flue at one end of said housing, an air heater in said flue, means for heating the air at opposite ends of the housing With an intermediate zone unprovided with heating means, means..

for causing Va movement of the air bodily through -the housing 'from the exit end toward the inlet to a point at the forward end of the unheated zone and for there discharging the moisture.laden air from the housing.

11.A dry kiln comprising a housing through which the material to bey dried is fed from one end to the other, a flue at one end of the housing, a cross flue connected therewith, a heater ing said first mentioned flue a second cross flue at the opposite end of the housing, means for heating the air at opposite ends of the housing,and means cooperating With said flue for maintaining a deadair zone therein at housing.

12. A dry the inletend of the L .kiln comprising a housing through which thev material to be dried is fed from one end to the other, a Hue at one l end of. the housing, a cross iiue connected therewith, a heater in said first mentioned flue, a second cross fiue adj aeent the opposite end of the housing, spaced heaters arranged at vopposite ends of the housing forming a zone intermediate said heaters un rovided with heating means, a `ilooring or said zone having valve controlled apertures therein, and means coperating with said iues for maintaining a dead'air zone at the inlet end of the housing.

13. A dry kiln comprising a housing through which the material'to be dried is fed from one end to the other, a flue at one end of the housing, a cross flue connected therewith, a second cross flue adjacent the opposite end of the housing, spaced heaters arranged at opposite ends of the housing, Jforming a zone between said heaters unprovided with heating means,

valves controlling apertures in the second flue, and a deiiector positioned adjacent the last mentioned apertures.

a flooring for said zone having valve controlled apertures,

14. A dry kiln lcomprising a housing through which the material to bedried is fed from one end to the others means for heating the air in said housing, an inlet Hue for admitting air to the exit end of said kiln, means for causing the .bodily movement of air through said kiln alternatively through a portion or the-entire len h thereof, said means comprising an exit ue arranged intermediate the ends of the kiln, an extension of said exit flue to the inlet end of the kiln, and means for opening or closing said extension.

In testimon whereof I ailix my signature in presence o two Witnesses.

f CHAS.- H. DINGMAN.

Witnesses:

NELLIE KINSELLA,

W. J. BELKNAP. 

